This invention relates generally to the field of surgical devices, and more particularly to an improved permanently implanted cardiac assist device for mechanically supporting the left ventricular pumping function of a failing human heart.
Various previous attempts to compensate for the loss of the natural pumping capacity of the heart by external assist devices are known in the art. It is also known to provide a total heart replacement by organic transplant or by substitution of a mechanical device. The problems arising from organic transplant are well-known and require little discussion. There have been two principal problems involved with mechanical devices, which are not readily overcome.
One problem is the occurrence of hemolysis caused by the continuous contact of the blood of the patient with intrinsically foreign materials. The second is a mechanical one, namely the difficulty of providing adequate power sources for the mechanical device in a practical and convenient fashion.
Some progress has been made over the last decade. In the Patent to Russo, U.S. Pat. No. 3,518,702, granted July 7, 1970, there is disclosed an implantable body-actuated artifical heart system which is powered and regulated by the chest and breathing muscles. The patent to Thoma, U.S. Pat. No. 4,034,742 granted July 12, 1977, shows a device, the operation of which is keyed to the electrocardiogram of the patient. The Cieszynski U.S. Pat. No. 4,078,267 granted Mar. 14, 1978, discloses a pump with a capacity four times that of the heart which operates at 1/4 the normal heart frequency.
Reference is made to my confidential disclosure document filed in the U.S. Patent and Trademark Office on May 18, 1978, under No. 071297.